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Biomedical subjects

S Heinrich

Publications and source records attributed to S Heinrich.

At least 19 recordsLinked to original sources
PubMed2006

Surfactant protein A--from genes to human lung diseases.

Surfactant associated protein-A (SP-A) is the most abundant pulmonary surfactant protein and belongs to the family of innate host defense proteins termed collectins. Besides pulmonary host defense, SP-A is also involved in the formation of pulmonary surfactant, as it is essential for the structure of tubular myelin. The human SP-A gene locus includes two functional genes, SFTPA1 and SFTPA2 which are expressed independently, and a pseudo gene. The largest amount of SP-A1 proteins assemble to larger molecular complexes, whereas SP-A2 forms mainly dimers and trimers. SP-A polymorphisms play a role in respiratory distress syndrome, allergic bronchopulmonary aspergillosis and idiopathic pulmonary fibrosis. The levels of SP-A are decreased in the lungs of patients with cystic fibrosis, respiratory distress syndrome and further chronic lung diseases. Future areas for clinical research include disease specific SP-A expression pattern and their functional consequences, the differential roles of SP-A1 and SP-A2 in human lung diseases, and therapeutical approaches to correct altered SP-A levels.

Humans↗
PubMed2005

[Current diagnosis and treatment of pancreatic cancer].

Adenocarcinoma of the pancreas (pancreatic cancer) is the most frequent tumor entity in the pancreas. While the results of surgical therapy of pancreatic cancer were disappointing in the past due to high perioperative mortality rates, resection of pancreatic cancer nowadays represents the standard treatment for non-metastatic cancer with a mortality rate below 5%. This decrease in perioperative mortality of the Whipple operation is inversely correlated to the case load of the hospital and the responsible surgeon, and is mainly related to improvements in the intensive care management, the surgical technique and patient selection. In particular, the perioperative use of octreotide resulted in a significant decrease in the rate of pancreatic fistula. Furthermore, modern staging examinations such as diagnostic laparoscopy, PET, or endoscopic ultrasound resulted in improved patient selection. In addition, the long-term results of the surgical treatment of pancreatic cancer has been improved by adjuvant and neoadjuvant chemotherapy in the past 10 years. Similar progress has been made in the palliative treatment of metastatic or locally advanced cancer. Nowadays, endoscopic procedures can replace surgical palliation of obstructive jaundice in most cases and sometimes even gastric outlet obstruction. Moreover, systemic chemotherapy using gemcitabine-based protocols has resulted in a significant prolongation of survival. However, further progress in the treatment of pancreatic cancer can only be achieved by an interdisciplinary management of this disease.

Adenocarcinoma↗
PubMed2004

No enhancement of fusion probability by the neutron halo of 6He.

Quantum tunnelling through a potential barrier (such as occurs in nuclear fusion) is very sensitive to the detailed structure of the system and its intrinsic degrees of freedom. A strong increase of the fusion probability has been observed for heavy deformed nuclei. In light exotic nuclei such as 6He, 11Li and 11Be (termed 'halo' nuclei), the neutron matter extends much further than the usual nuclear interaction scale. However, understanding the effect of the neutron halo on fusion has been controversial--it could induce a large enhancement of fusion, but alternatively the weak binding energy of the nuclei could inhibit the process. Other reaction channels known as direct processes (usually negligible for ordinary nuclei) are also important: for example, a fragment of the halo nucleus could transfer to the target nucleus through a diminished potential barrier. Here we study the reactions of the halo nucleus 6He with a 238U target, at energies near the fusion barrier. Most of these reactions lead to fission of the system, which we use as an experimental signature to identify the contribution of the fusion and transfer channels to the total cross-section. At energies below the fusion barrier, we find no evidence for a substantial enhancement of fusion. Rather, the (large) fission yield is due to a two-neutron transfer reaction, with other direct processes possibly also involved.

Journal Article↗
PubMed2003

Right hemihepatectomy for bile duct injury following laparoscopic cholecystectomy.

Laparoscopic cholecystectomy (LC) has become the treatment of choice for patients with symptomatic cholecystolithiasis. But with the introduction of this technique, the incidence of bile duct injuries has increased. We report the case of a 33-year-old man who was transferred from an affiliated hospital to our department for the treatment of a bile duct injury 2 weeks after LC. Prior to transfer, a laparotomy had been performed, with insertion of a T-tube and a Robinson drain on day 5 after LC. Endoscopic retrograde cholangiography (ERC) on admission day revealed an extensive defect of the right biliary system, which could not be treated endoscopically. An emergency laparotomy had to be performed at night for acute bleeding from the portal vein. Due to massive inflammation in the porta hepatis and intraparenchymal destruction of the right bile duct, liver resection was performed 2 days later, after the patient had stabilized in the intensive care unit (ICU). The patient had a prolonged postoperative course, but he finally recovered well from these operations. In conclusion, the management of bile duct injuries should include ultrasound to detect and drain fluid collections and ERC to classify the injury. Emergency laparotomy should never be performed without these examinations, since the majority of bile duct injuries can be treated endoscopically. Surgery for this serious complication should always be performed at specialized centers for hepatobiliary surgery.

Adult↗
PubMed2002

[Colorectal carcinoma--surgical interventions in metastases].

Metastases from colorectal cancer should be resected, if surgery can achieve a complete freedom of tumor and if the procedure is associated with a low morbidity and mortality rate. Multiple sites of metastases do not represent a contraindication for surgery, if complete excision appears possible. The resulting 5-year survival rate after resection of pulmonary and liver metastases is in the range of 20-30%, and the survival is influenced by the extent of the distant spread and the stage of the primary tumor.--The aim of neoadjuvant chemotherapy is the improvement of resectability and of postoperative prognosis. Postoperative regional chemotherapy did not show a significant survival benefit for the patient, only the recurrence free survival rate is increased. Due to the complex disease and the necessary technical knowledge the treatment outcome is better in the cooperation of colorectal specialists from surgery, gastroenterology and medical and radiation oncology.

Chemotherapy, Adjuvant↗
PubMed2002

[Indocyanine green angiography in choroid metastases].

BACKGROUND: Up to now the diagnosis of choroidal tumors was mainly based on ophthalmoscopy and ultrasound examination. Indocyanine green angiography allows the identification of vascular patterns in these tumors, which could be helpful in the differential diagnosis. The aim of the study was to characterize the staining patterns of choroidal metastases. METHODS: In the years 1996-2000 we performed ICG-A of 15 choroidal metastasis using the scanning laser ophthalmoscope from Rodenstock. The mean tumor height was 3.7 mm (2.0-9.0). These angiographies were compared to the angiographies of 38 choroidal malignant melanomas with a mean height of 3.6 mm (1.4-6-6). RESULTS: All metastases showed a blockage of the background staining and a patchy staining of the tumor surface. Intratumoral vessels could be detected in 13% of all cases of metastases. The choroidal melanomas examined showed a blockage of the background staining in all cases and tumor vessels in 89%. CONCLUSION: The angiographic picture of the metastatic lesions was characteristic. Intratumoral vessels could not be detected using ICG-A. Most of the metastases showed a patchy staining of the tumor surface.

Angiography↗
PubMed2001

Phase II study of weekly 24-hour intra-arterial high-dose infusion of 5-fluorouracil and folinic acid for liver metastases from colorectal carcinomas.

BACKGROUND: A multicenter phase II trial was initiated in order to evaluate the weekly, high-dose 24-hour infusion of 5-fluorouracil (5-FU) plus folinic acid (FA) in patients with unresectable colorectal cancer hepatic metastases. PATIENTS AND METHODS: A weekly hepatic arterial infusion (HAI) of FA 500 mg/m2 followed by a 24-hour infusion of 5-FU 2,600 mg/m2 (later reduced to 2,200 mg/m2) was given via a surgically implanted intra-arterial port system. One treatment cycle consisted of six weekly applications followed by a two-week rest period. Toxicity was assessed according to the WHO criteria. Chemotherapy was continued until disease progression or complete response occurred. RESULTS: A total of 50 patients (40 chemonaive, 10 pre-treated) entered this trial. An objective tumor response occurred in 28 patients (56%), while 13 patients (26%) had stable disease. The median progression free survival was 12 months, and the median survival 22.3 months. Due to a high rate of gastrointestinal side-effects in the initial phase of the trial, the dosage of 5-FU was reduced to 2,200 mg/m2 for all subsequent patients. Diarrhea and nausea led to a dose reduction in 40% of applications and 24% of patients, respectively. One patient died of cardiac insufficiency unrelated to chemotherapy before response evaluation. CONCLUSIONS: This HAI approach using high-dose 5-FU was relatively well tolerated when 2,200 mg/m2 instead of 2,600 mg/m2 was used. The activity of this regimen is promising and warrants further evaluation and modification.

Adenocarcinoma↗
PubMed2000

Regional chemotherapy in the treatment of advanced pancreatic cancer--is it relevant?

The treatment of pancreatic cancer is still problematic for physicians. Only 15% of patients present with resectable tumours, and systemic chemotherapy is of limited effectiveness. In order to achieve higher local drug concentrations in the tumour without causing the side-effects of a comparable level of systemic treatment, regional chemotherapy has been introduced as an alternative treatment. Several techniques have been developed over recent years, these include: celiac axis infusion (CAI), CAI with microspheres or haemofiltration, aortic stop flow (ASF) and isolated hypoxic perfusion (IHP). Whilst several authors have reported improved response rates and a prolongation of median survival time, these results have not been confirmed by others. In addition, the incidence of side-effects and the rate of technical complications have been reported to be high during regional chemotherapy. Except for a single trial containing 14 patients, no randomised trial comparing systemic and regional chemotherapy has been conducted. For these reasons, none of the reported treatment regimens can be considered to be standard treatment and in order to evaluate, if regional chemotherapy is indeed superior to systemic chemotherapy, randomised trials must be conducted.

Antineoplastic Agents↗
PubMed2000

Relevance of locoregional chemotherapy in patients with liver metastases from colorectal primaries.

Progression of colorectal cancer can occur primarily isolated in the liver. But, only the minority of the affected patients is eligible for surgery. Initially, systemic chemotherapy was ineffective in the treatment of unresectable hepatic metastases. For this reason, intraarterial chemotherapy was introduced as treatment alternative to the systemic chemotherapy. Long-term intraarterial chemotherapy regimens with FUDR in patients with colorectal liver metastases, using implantable pumps and ports, resulted in improved response rates, which was confirmed by several randomized trials. However, an improvement in median survival has not yet been demonstrated after regional chemotherapy of hepatic metastases. Since the intraarterial therapy with floxuridine (FUDR) had been reported to result in a high rate of local toxicity, 5-fluorouracil (5-FU) was introduced into regional chemotherapy of the liver. A randomized trial demonstrated superiority of intraarterial 5-FU versus intraarterial FUDR therapy. Despite these reports about high response rates, the benefit of intraarterial chemotherapy remains questionable, because it has not yet resulted in a prolongation of median survival. For this reason, long-term regional chemotherapy cannot be considered as standard treatment and should therefore not be conducted outside controlled clinical trials. Further evaluations on this technique should only be performed in experienced centers.

Antimetabolites, Antineoplastic↗
PubMed1999

Fibrosarcoma in infants and children: a retrospective analysis - overdiagnosis in earlier years.

During a 30-year period, 22 patients considered to have a fibrosarcoma (FS) were treated. In a retrospective study the clinicopathologic findings were summarized. With histologic and immunohistochemical re-evaluation, the diagnosis was confirmed in 8 cases. For 6 further patients FS was very probable but specimens were not available. In 8 cases the diagnosis was revised and benign lesions were found in 7. Two patients with irresectable tumors died (infantile FS, FS of mesentery and retroperitoneum). After repeated local recurrences and spread on the affected extremity, an amputation was life-saving in 1 boy. In earlier years many tumors were classified as FSs. Today, immunohistochemistry and molecular-biological methods are valuable tools to clearly identify these tumors. Wide local excision or en-bloc resection without sacrificing any significant function of the part should be the primary form of treatment in infants. Primary re-excision after incomplete excision should have priority over any adjuvant treatment. Preoperative chemotherapy may avoid incomplete resection or mutilation in cases with extended congenital FS.

Child↗
PubMed1999

[Technique and pathophysiology of isolated hypoxic perfusion of the abdomen].

Isolated hypoxic perfusion (IHP) is a commonly used technique in the treatment of abdominal malignancies. During a phase II-study the pathophysiology of this technique was explored in patients with advanced pancreatic cancer. Twenty perfusions of the abdomen were performed in 17 patients. Under general anesthesia, femoral vessels were dissected and two balloon catheters were inserted into aorta and vena cava cranial the celiac trunk and the hepatic veins. After instillation of 40 mg of Mitomycin C (MMC) into the running perfusion system, the perfusion was maintained for further 20 minutes. Blood samples were taken in 5-minute intervals to determine pH value, blood gases as well as concentrations of electrolytes, lactate and MMC in the arterial blood. Simultaneously, blood samples were taken from the perfusion blood via a side-port of the extracorporeal perfusion system. Additionally, perfusion pressures, arterial and central venous pressure, heart rate, and the pressure in the aorta distal the balloon catheter were registered continuously. All 20 perfusions had been undertaken without perioperative mortality. After inflating the balloon catheters, blood pressure and heart rate increased rapidly. Within 5 minutes of perfusion an increase in pCO2 and the concentrations of K+ and lactate in the perfusate were registered, while pH and pO2 decreased. Fifteen minutes after instillation of MMC, concentrations of MMC in arterial and perfusion blood were equal. Twenty-four hours after the perfusion all parameters had returned to normal values. IHP was well feasible in 20 consecutive perfusions without major technical problems. A distinct but tolerable combined acidosis resulted from IHP. Despite the exact positioning and control of the balloon catheters a complete isolation was not possible.

Acid-Base Equilibrium↗
PubMed1999

Current role of scapulectomy.

Tumors of the scapula are an unusual clinical challenge. Partial or complete resection of the scapula, with its attached musculoaponeurotic tissue, is a seldom used technique for the treatment of primary bone and soft tissue tumors, as well as selected metastatic involvement of the scapula. Scapulectomy may allow wide margins of resection without amputation. The purpose of this study is to review our recent experience with scapulectomy. This study describes the recent experience with scapulectomy by the Section of Surgical Oncology and the Department of Orthopedics at Louisiana State Medical Center (New Orleans, LA). Between 1994 and 1998, 12 patients (between 16 and 79 years of age) underwent a resection of the scapula. Eleven of these patients had soft tissue tumors; one had a metastasis from a thyroid carcinoma. Six of these patients underwent a scapulectomy as a primary treatment, five for recurrence. Six patients also received postoperative radiation and/or chemotherapy. The follow-up ranged from 6 months to 4 years. There was no mortality or wound infection associated with scapulectomy. All patients had normal hand and wrist function after surgery. Three distant recurrences occurred, with no local or regional failures encountered during the follow-up period. Scapulectomy can result in excellent local tumor control. Whereas some loss of active shoulder motion may occur, hand, wrist and elbow function is preserved. Although maintenance of shoulder function should not take precedence over adequacy of resection, scapulectomy remains an excellent procedure for malignant disease that preserves hand, wrist, and elbow function.

Adolescent↗
PubMed1998

Hyperosmotic induction of the mitogen-activated protein kinase phosphatase MKP-1 in H4IIE rat hepatoma cells.

The action of hyperosmotic stress on the MAP kinase phosphatase MKP-1 mRNA expression was studied in H4IIE rat hepatoma cells. Hyperosmotic (405 mosmol/L) challenge of the cells led to a transient expression of MKP-1 mRNA, which was maximal after 6-8 h and disappeared completely after 24 h. Hyperosmotic MKP-1 mRNA induction was preceded by a transient activation of the MAP kinases Erk-1, Erk-2, and JNK-2, which were not prerequisite for MKP-1 mRNA accumulation. However, the hyperosmolarity-induced MKP-1 mRNA expression was sensitive to antioxidants and to inhibition of p38 by SB203580. A reduced sensitivity of Erk-1/Erk-2 to other stimuli was found after prolonged hyperosmotic exposure. The data are consistent with a hyperosmolarity-induced MKP-1 expression via reactive oxygen intermediates and p38, which may participate in the termination of MAP kinase activation and contribute to desensitization of the MAP kinases after prolonged hyperosmotic exposure of the cells.

Animals↗
PubMed1998

Isolated hypoxic perfusion with mitomycin C in patients with advanced pancreatic cancer.

AIMS: Chemotherapy as a palliative therapy option for patients with advanced pancreatic cancer remains disappointing. Some authors have recently claimed high response rates and a prolongation of median survival after regional chemotherapy. Isolated perfusion may result in the highest drug concentrations within the target tissue without causing systemic side-effects. An established, commercially available system of isolated hypoxic perfusion (IHP) was therefore evaluated in patients with unresectable or recurrent pancreatic cancer. PATIENTS AND METHODS: IHP was performed in 17 patients with unresectable pancreatic cancer. Five women and 12 men with a median age of 61 years were treated. A 20-min isolated hypoxic perfusion was performed after 40 mg of mitomycin C (MMC) had been instilled into the running perfusion system over 5 min. Tumour response was evaluated by CT-scan 6 weeks after IHP. RESULTS: Twenty perfusions were carried out in 17 patients. Within 10 min of perfusion, the perfusate's PO2 decreased to 13% of the baseline value. Five minutes after the infusion of MMC a local concentration of 15.2 mg/litre was observed. Toxicity-related deaths did not occur. Nausea and vomiting (NCI> or =II: 12 episodes) were the most frequently observed toxicities after IHP. In five patients (29%) a deep vein thrombosis occurred. None of the treated patients responded to the regimen used in this trial. The median survival time after IHP was 4.2 months (range 1.3-21). CONCLUSIONS: The overall rate of side-effects and complications after IHP was high. In spite of some hopeful reports on this treatment in recent years, IHP did not show any benefit in terms of tumour response or median survival. On the basis of these experiences, this procedure should no longer be used as treatment for patients with unresectable or recurrent pancreatic cancer.

Aged↗
PubMed1998

Acute clozapine overdose: plasma concentration and outcome.

Clozapine is a tricyclic dibenzodiazepine derivative that is classified as an "atypical neuroleptic" drug for treatment of psychotic diseases. A 19-year-old schizophrenic female, treated with 400 mg clozapine per day, was admitted to the emergency department after ingestion of 5000 mg (50 x 100 mg tablets) of clozapine. Clozapine plasma level 2.5 hours after ingestion was 3.8 microg/ml (normal range 0.2-0.7 microg/ml) and very high in gastric lavage. Contrary to reported cases with such high plasma concentrations the patient suffered only from somnolence with intermittent periods of agitation and a mild anticholinergic syndrome with sinus tachycardia and slight hypotension. After detoxication with gastric lavage and short-term administration of pyridostigmine she remained stable, and 24 hours after ingestion she was transferred to the psychiatric unit without further sequelae. To prevent late-onset complications she was carefully monitored for five days. The clozapine plasma level 24 hours after the first measurement was normal. This case and others reported in the literature confirm that signs and symptoms after clozapine intoxication are variable and that high plasma levels are not lethal in every case.

Adult↗
PubMed1998

Extended hemipelvectomy in a Jehovah's Witness with erythropoietin support.

The care of patients refusing blood transfusion who require major ablative surgery for malignancy is a continuing challenge. The use of recombinant human erythropoietin is clearly efficacious in patients with renal disease and may be useful in anemic patients who refuse transfusion. Herein, we report a successful extended hemipelvectomy in a Jehovah's Witness using recombinant human erythropoietin support.

Adult↗
PubMed1998

[Isolated hypoxic perfusion with mitomycin C confers no benefit for patients with advanced pancreatic carcinoma].

Since therapy options in the treatment of advanced pancreatic cancer are rare, the present study has investigated whether patients with advanced pancreatic cancer may profit from isolated hypoxic perfusion (IHP) of the abdomen with mitomycin C. None of the 17 treated patients responded to IHP with mitomycin C, and the survival time corresponded to that of untreated patients. On the basis of these results, this procedure should no longer be used as treatment for patients with advanced pancreatic cancer.

Adenocarcinoma↗